package com.ruoyi.common.utils;

import java.security.AlgorithmParameters;

import java.security.Key;

import java.security.SecureRandom;

import java.security.Security;

import java.util.Arrays;

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import javax.crypto.spec.IvParameterSpec;

import javax.crypto.spec.SecretKeySpec;

public class AES128Util {

//算法名

    public static final String KEY_ALGORITHM = "AES";

//加解密算法/模式/填充方式

//可以任意选择，为了方便后面与iOS端的加密解密，采用与其相同的模式与填充方式

//ECB模式只用密钥即可对数据进行加密解密，CBC模式需要添加一个参数iv

    public static final String CIPHER_ALGORITHM = "AES/CBC/PKCS7Padding";

//生成密钥

    private static byte[] generateKey(String aesKey) throws Exception{

       // Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

/*

KeyGenerator kgen =KeyGenerator.getInstance(KEY_ALGORITHM);

kgen.init(128, new SecureRandom(aesKey.getBytes()));

SecretKey secretKey = kgen.generateKey();

byte[] encodeFormat = secretKey.getEncoded();

SecretKeySpec keySpec = new SecretKeySpec(encodeFormat, "AES");

return keySpec.getEncoded();

*/

        return aesKey.getBytes();

    }

//生成iv

    private static AlgorithmParameters generateIV(String ivVal) throws Exception{

//iv 为一个 16 字节的数组，这里采用和 iOS 端一样的构造方法，数据全为0

//byte[] iv = new byte[16];

//Arrays.fill(iv, (byte) 0x00);

//Arrays.fill(iv,ivVal.getBytes());

        byte[]iv=ivVal.getBytes();

        AlgorithmParameters params = AlgorithmParameters.getInstance(KEY_ALGORITHM);

        params.init(new IvParameterSpec(iv));

        return params;

    }

//转化成JAVA的密钥格式

    private static Key convertToKey(byte[] keyBytes) throws Exception{

        SecretKey secretKey = new SecretKeySpec(keyBytes,KEY_ALGORITHM);

        return secretKey;

    }

//加密

    public static String encrypt(String plainText,String aesKey,String ivVal) throws Exception {

        byte[] data=plainText.getBytes();

        AlgorithmParameters iv=generateIV(ivVal);

        byte[] keyBytes = generateKey(aesKey);

//转化为密钥

        Key key = convertToKey(keyBytes);

        //Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);

//设置为加密模式

        cipher.init(Cipher.ENCRYPT_MODE, key,iv);

        byte[] encryptData= cipher.doFinal(data);

        return bytesToHexString(encryptData);

    }

//解密

    public static String decrypt(String encryptedStr,String aesKey,String ivVal) throws Exception{

        byte[] encryptedData=hexStringToByte(encryptedStr);

        byte[] keyBytes = generateKey(aesKey);

        Key key = convertToKey(keyBytes);

        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);

        AlgorithmParameters iv=generateIV(ivVal);

//设置为解密模式

        cipher.init(Cipher.DECRYPT_MODE, key,iv);

        byte[] decryptData=cipher.doFinal(encryptedData);

        return new String(decryptData);

    }

    /**

     * 十六进制字符串转换成数组

     * @param hex

     * @return

     */

    private static byte[] hexStringToByte(String hex) {

        int len = (hex.length() / 2);

        byte[] result = new byte[len];

        char[] achar = hex.toCharArray();

        for (int i = 0; i < len; i++) {

            int pos = i * 2;

            result[i] = (byte) (toByte(achar[pos]) << 4 | toByte(achar[pos + 1]));

        }

        return result;

    }

    private static byte toByte(char c) {

        byte b = (byte) "0123456789abcdef".indexOf(c);

        return b;

    }

    /**

     * 把字节数组转换成16进制字符串

     * @param bArray

     * @return

     */

    private static final String bytesToHexString(byte[] bArray) {

        StringBuffer sb = new StringBuffer(bArray.length);

        String sTemp;

        for (int i = 0; i < bArray.length; i++) {

            sTemp = Integer.toHexString(0xFF & bArray[i]);

            if (sTemp.length() < 2)

                sb.append(0);

            sb.append(sTemp.toLowerCase());

        }

        return sb.toString();

    }
}
